Just got the email that "Bing Business Portal is now Bing Places for Business." Do we care? Should we care?

Yes, although not the major player that google is for example, Bing still has a decent share of the market. There are always side effects from them transitioning anything.
My question is what does this mean to your business places account on Bing? Does is change your ranking on the map when someone types in keywords for your industry? Chances are it may.
So short answer - yes , you should probably care IMHO, then again it may not change anything.

I care in as much that it's a more streamlined interface and claiming process than the old. The extraneous business enhancements (QR Codes, Mobile Sites, printing, etc) are something I'm glad to see disappear from the process. I would assume some of them (coupons and deal creation) will return in some better implemented, premium listing version or some such. The "Places" naming will be either easier for people or more difficult, I guess. lol Other than that, I don't see too much to care about more or less than the previous iteration.

Looking at my analytics, in the last year 2.81% of traffic I received from search engines came from Bing. Am I not optimizing for Bing because of crappy traffic #s, or am I getting crappy traffic #s because I don't optimize for Bing? Which is the chicken and which is the egg?

Crap, one more thing to do. When I started this business I had this crazy idea that I'd be spending most of my time actually, you know, doing landscape designs...

I use Google as my base, optimize the various Places/Local accounts, and let the SEO gods do their work. I find that if I really only concern myself with Google ranking, Bing/Yahoo reflect it as well. Case in point, the keywords/cities for a project I've been paying extra attention to (I've talked about it here over the last couple of months), have Google rankings of 1 or 2. In Bing and Yahoo, I just looked and some of those same keywords actually tend to be ranked 1 AND 2 (specific sub-page is always first, with the root domain link ranking second).

On my site tracker it shows only 11% of traffic coming from Bing. I realize 11% is bigger than no percent, but for me I am not worrying about it for now. If you're a huge business squeezing every last marketing opportunity there is, it may be worth looking into.